Bladder Mucosal Protectant Pregnancy: Avoid in pregnancy — insufficient safety data

Pentosan Polysulfate Sodium

Brand names: Elmiron

Adult dose

Dose: 100 mg three times daily

Route: Oral

Frequency: Three times daily (1 hour before meals or 2 hours after)

Max: 300 mg/day

Licensed for interstitial cystitis / bladder pain syndrome (IC/BPS). Minimum treatment duration 3 months before assessing response; full benefit may take 6-12 months

Paediatric dose

Dose: Not applicable N/A/kg

Route: Oral

Frequency: Not applicable

Max: Not applicable

Not applicable

Dose adjustments

Renal

Use with caution in renal impairment

Hepatic

Use with caution in hepatic impairment

Paediatric weight-based calculator

Patient weight (kg)

Not applicable

Clinical pearls

MHRA 2020 safety alert: Pentosan polysulfate sodium associated with rare but serious pigmentary maculopathy — cumulative dose-dependent retinal toxicity; ophthalmology review recommended before starting and annually thereafter
Only licensed oral pharmacotherapy for interstitial cystitis in the UK — mechanism thought to replenish deficient glycosaminoglycan (GAG) layer of urothelium
Alopecia is the most common distinctive side effect — warn patients; reversible on dose reduction or stopping
Response is slow — inform patients to continue treatment for at least 3-6 months before deciding on efficacy; premature discontinuation common
European ESSIC and NICE guidance: IC/BPS management is multimodal — lifestyle, physiotherapy, intravesical instillations, and oral therapy; pentosan is one component

Contraindications

Hypersensitivity to pentosan polysulfate

Side effects

Alopecia (reversible, dose-dependent — most distinctive side effect)
GI upset (nausea, diarrhoea, dyspepsia)
Headache
Elevated liver enzymes
Bleeding risk (anticoagulant-like properties)
Maculopathy (MHRA 2020 safety warning — rare but serious)

Interactions

Anticoagulants (additive bleeding risk — monitor INR if on warfarin)
Aspirin and NSAIDs (additive antiplatelet effect)

Monitoring

Ophthalmology review (maculopathy surveillance annually)
LFTs
Coagulation (if on anticoagulants)
Symptom scores (ICSI/ICPI)
Hair loss

Reference: BNFc; BNF 90; MHRA Drug Safety Update 2020 (pentosan maculopathy); ESSIC Guidelines; EAU IC/BPS Guidelines 2024. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways